<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        * {
            padding: 0;
            margin: 0;
        }
        
        html,
        body {
            height: 100%;
        }
        
        .box {
            font-size: 40px;
            text-align: center;
            width: 100%;
            height: 100%;
            color: #fff;
        }
        
        .box1 {
            background: url(img/avds.jpg);
            background-attachment: fixed;
            background-size: 100% 100%;
        }
        
        .box2 {
            background: url(img/bg1_1600.jpg);
            background-attachment: fixed;
        }
        
        .box3 {
            background: url(img/bg3_1600.jpg);
            background-attachment: fixed;
        }
    </style>
</head>

<body>
    <div class="box box1">第一个图</div>
    <div class="box box2">第二个图</div>
    <div class="box box3">第三个图</div>
</body>

</html>